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Premont RT, Reynolds JD, Zhang R, Stamler JS. Red Blood Cell-Mediated S-Nitrosohemoglobin-Dependent Vasodilation: Lessons Learned from a β-Globin Cys93 Knock-In Mouse. Antioxid Redox Signal 2021; 34:936-961. [PMID: 32597195 PMCID: PMC8035927 DOI: 10.1089/ars.2020.8153] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 06/25/2020] [Indexed: 12/25/2022]
Abstract
Significance: Red blood cell (RBC)-mediated vasodilation plays an important role in oxygen delivery. This occurs through hemoglobin actions, at least in significant part, to convert heme-bound nitric oxide (NO) (in tense [T]/deoxygenated-state hemoglobin) into vasodilator S-nitrosothiol (SNO) (in relaxed [R]/oxygenated-state hemoglobin), convey SNO through the bloodstream, and release it into tissues to increase blood flow. The coupling of hemoglobin R/T state allostery, both to NO conversion into SNO and to SNO release (along with oxygen), under hypoxia supports the model of a three-gas respiratory cycle (O2/NO/CO2). Recent Advances: Oxygenation of tissues is dependent on a single, strictly conserved Cys residue in hemoglobin (βCys93). Hemoglobin couples SNO formation/release at βCys93 to O2 binding/release at hemes ("thermodynamic linkage"). Mice bearing βCys93Ala hemoglobin that is unable to generate SNO-βCys93 establish that SNO-hemoglobin is important for R/T allostery-regulated vasodilation by RBCs that couple blood flow to tissue oxygenation. Critical Issues: The model for RBC-mediated vasodilation originally proposed by Stamler et al. in 1996 has been largely validated: SNO-βCys93 forms in vivo, dilates blood vessels, and is hypoxia-regulated, and RBCs actuate vasodilation proportionate to hypoxia. Numerous compensations in βCys93Ala animals to alleviate tissue hypoxia (discussed herein) are predicted to preserve vasodilatory responses of RBCs but impair linkage to R/T transition in hemoglobin. This is borne out by loss of responsivity of mutant RBCs to oxygen, impaired blood flow responses to hypoxia, and tissue ischemia in βCys93-mutant animals. Future Directions: SNO-hemoglobin mediates hypoxic vasodilation in the respiratory cycle. This fundamental physiology promises new insights in vascular diseases and blood disorders.
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Affiliation(s)
- Richard T. Premont
- Institute for Transformative Molecular Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
| | - James D. Reynolds
- Institute for Transformative Molecular Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
- Department of Anesthesiology and Perioperative Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Rongli Zhang
- Institute for Transformative Molecular Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- Department of Medicine, Cardiovascular Research Institute, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Jonathan S. Stamler
- Institute for Transformative Molecular Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
- Department of Medicine, Cardiovascular Research Institute, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
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2
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Wei F, Zhao L, Jing Y. Hemoglobin-derived peptides and mood regulation. Peptides 2020; 127:170268. [PMID: 32070683 DOI: 10.1016/j.peptides.2020.170268] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 02/02/2020] [Accepted: 02/04/2020] [Indexed: 12/12/2022]
Abstract
Evidence accumulated over the past decades has revealed that red blood cells and hemoglobin (Hb) in the blood play important roles in modulating moods and emotions. The number of red blood cells affects the mood. Hb is the principal content in the red blood cells besides water. Denatured Hb is hydrolyzed to produce bioactive peptides. RVD-hemopressin α (RVD-Hpα), which is a fragment of α-chain (95-103) in Hb, functions as a negative allosteric modulator of cannabinoid receptor 1 and a positive allosteric modulator of cannabinoid receptor 2. Hemorphins, which are fragments of β-chain in Hb, exert their effects on opioid receptors. Two hemorphins, namely, LVV-hemorphin-6 and LVV-hemorphin-7, could induce anxiolytic-like effects. The use of Hb-derived bioactive peptides for the treatment of mood disorders is desirable due to cannabinoid-opioid cross modulation and the critical roles of the two systems in physiological processes, such as memory, mood and emotion.
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Affiliation(s)
- Fengmei Wei
- Department of Physiology and Psychology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, Gansu, 730000, PR China
| | - Long Zhao
- Department of Orthopaedics, Lanzhou University First Affiliated Hospital, Lanzhou, Gansu, 730000, PR China
| | - Yuhong Jing
- Institute of Anatomy and Histology & Embryology, Neuroscience, School of Basic Medical Sciences, Lanzhou University, Lanzhou, Gansu, 730000, PR China; Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Lanzhou University, Lanzhou, Gansu, 730000, PR China.
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3
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Dvořáková V, Horníková M, Němcová L, Marková S, Kotlík P. Regulatory Variation in Functionally Polymorphic Globin Genes of the Bank Vole: A Possible Role for Adaptation. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2019.00514] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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Pu P, Lu S, Niu Z, Zhang T, Zhao Y, Yang X, Zhao Y, Tang X, Chen Q. Oxygenation properties and underlying molecular mechanisms of hemoglobins in plateau zokor ( Eospalax baileyi). Am J Physiol Regul Integr Comp Physiol 2019; 317:R696-R708. [PMID: 31508994 DOI: 10.1152/ajpregu.00335.2018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The plateau zokor (Eospalax baileyi) is a species of subterranean rodent endemic to the Tibetan Plateau. It is well adapted to the cold and hypoxic and hypercapnic burrow. To study the oxygenation properties of plateau zokor hemoglobins (Hbs), we measured intrinsic Hb-O2 affinities and their sensitivities to pH (Bohr effect); CO2; Cl-, 2,3-diphosphoglycerate (DPG); and temperature using purified Hbs from zokor and mouse. The optimal deoxyHb model of plateau zokor was constructed and used to study its structural characteristics by molecular dynamics simulations. O2 binding results revealed that plateau zokor Hbs exhibit remarkably high intrinsic Hb-O2 affinity, low CO2 effects compared with human and the relatively low anion allosteric effector sensitivities (DPG and Cl-) at normal temperature, which would safeguard the pulmonary Hb-O2 loading under hypoxic and hypercapnic conditions. Furthermore, the high anion allosteric effector sensitivities at low temperature and low temperature sensitivities of plateau zokor Hbs would facilitate the releasing of O2 in cold extremities and metabolic tissues. However, the high Hb-O2 affinity of plateau zokor is not compensated by high pH sensitivity as the Bohr factors of plateau zokor Hbs were as low as those of mouse. The results of molecular dynamics simulations revealed the reduced hydrogen bonding between the α1β1- and α2β2-dimer interface of deoxyHb in zokor compared with mouse. It may be the primary mechanism of the high intrinsic Hb-O2 affinities in zokor. Specifically, substitution of the 131Ser→Asn in the α2-chain weakened the connection between α1- and β2-subunit.
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Affiliation(s)
- Peng Pu
- Institute of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, Lanzhou, Gansu, China
| | - Songsong Lu
- Faculty of Forestry, Gansu Agricultural University, Lanzhou, Gansu, China
| | - Zhiyi Niu
- Institute of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, Lanzhou, Gansu, China
| | - Tao Zhang
- Institute of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, Lanzhou, Gansu, China
| | - Yaofeng Zhao
- Institute of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, Lanzhou, Gansu, China
| | - Xingwen Yang
- Institute of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, Lanzhou, Gansu, China
| | - Yao Zhao
- Institute of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, Lanzhou, Gansu, China
| | - Xiaolong Tang
- Institute of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, Lanzhou, Gansu, China
| | - Qiang Chen
- Institute of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, Lanzhou, Gansu, China
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5
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Hoffmann FG, Vandewege MW, Storz JF, Opazo JC. Gene Turnover and Diversification of the α- and β-Globin Gene Families in Sauropsid Vertebrates. Genome Biol Evol 2018; 10:344-358. [PMID: 29340581 PMCID: PMC5786229 DOI: 10.1093/gbe/evy001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/09/2018] [Indexed: 11/24/2022] Open
Abstract
The genes that encode the α- and β-chain subunits of vertebrate hemoglobin have served as a model system for elucidating general principles of gene family evolution, but little is known about patterns of evolution in amniotes other than mammals and birds. Here, we report a comparative genomic analysis of the α- and β-globin gene clusters in sauropsids (archosaurs and nonavian reptiles). The objectives were to characterize changes in the size and membership composition of the α- and β-globin gene families within and among the major sauropsid lineages, to reconstruct the evolutionary history of the sauropsid α- and β-globin genes, to resolve orthologous relationships, and to reconstruct evolutionary changes in the developmental regulation of gene expression. Our comparisons revealed contrasting patterns of evolution in the unlinked α- and β-globin gene clusters. In the α-globin gene cluster, which has remained in the ancestral chromosomal location, evolutionary changes in gene content are attributable to the differential retention of paralogous gene copies that were present in the common ancestor of tetrapods. In the β-globin gene cluster, which was translocated to a new chromosomal location, evolutionary changes in gene content are attributable to differential gene gains (via lineage-specific duplication events) and gene losses (via lineage-specific deletions and inactivations). Consequently, all major groups of amniotes possess unique repertoires of embryonic and postnatally expressed β-type globin genes that diversified independently in each lineage. These independently derived β-type globins descend from a pair of tandemly linked paralogs in the most recent common ancestor of sauropsids.
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Affiliation(s)
- Federico G Hoffmann
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University.,Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University
| | | | - Jay F Storz
- School of Biological Sciences, University of Nebraska
| | - Juan C Opazo
- Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
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6
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Strážnická M, Marková S, Searle JB, Kotlík P. Playing Hide-and-Seek in Beta-Globin Genes: Gene Conversion Transferring a Beneficial Mutation between Differentially Expressed Gene Duplicates. Genes (Basel) 2018; 9:genes9100492. [PMID: 30321987 PMCID: PMC6209878 DOI: 10.3390/genes9100492] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 10/07/2018] [Accepted: 10/10/2018] [Indexed: 12/17/2022] Open
Abstract
Increasing evidence suggests that adaptation to diverse environments often involves selection on existing variation rather than new mutations. A previous study identified a nonsynonymous single nucleotide polymorphism (SNP) in exon 2 of two paralogous β-globin genes of the bank vole (Clethrionomys glareolus) in Britain in which the ancestral serine (Ser) and the derived cysteine (Cys) allele represent geographically partitioned functional variation affecting the erythrocyte antioxidative capacity. Here we studied the geographical pattern of the two-locus Ser/Cys polymorphism throughout Europe and tested for the geographic correlation between environmental variables and allele frequency, expected if the polymorphism was under spatially heterogeneous environment-related selection. Although bank vole population history clearly is important in shaping the dispersal of the oxidative stress protective Cys allele, analyses correcting for population structure suggest the Europe-wide pattern is affected by geographical variation in environmental conditions. The β-globin phenotype is encoded by the major paralog HBB-T1 but we found evidence of bidirectional gene conversion of exon 2 with the low-expression paralog HBB-T2. Our data support the model where gene conversion reshuffling genotypes between high- and low- expressed paralogs enables tuning of erythrocyte thiol levels, which may help maintain intracellular redox balance under fluctuating environmental conditions. Therefore, our study suggests a possible role for gene conversion between differentially expressed gene duplicates as a mechanism of physiological adaptation of populations to new or changing environments.
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Affiliation(s)
- Michaela Strážnická
- Laboratory of Molecular Ecology, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, 27721 Liběchov, Czech Republic.
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, 12844 Prague 2, Czech Republic.
- Department of Animal Science and Food Processing, Faculty of Tropical AgriSciences, Czech University of Life Sciences Prague, Kamýcká 129, 165 00 Prague 6-Suchdol, Czech Republic.
| | - Silvia Marková
- Laboratory of Molecular Ecology, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, 27721 Liběchov, Czech Republic.
| | - Jeremy B Searle
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA.
| | - Petr Kotlík
- Laboratory of Molecular Ecology, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, 27721 Liběchov, Czech Republic.
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA.
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7
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Kettisen K, Strader MB, Wood F, Alayash AI, Bülow L. Site-directed mutagenesis of cysteine residues alters oxidative stability of fetal hemoglobin. Redox Biol 2018; 19:218-225. [PMID: 30193183 PMCID: PMC6126208 DOI: 10.1016/j.redox.2018.08.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 08/18/2018] [Accepted: 08/20/2018] [Indexed: 01/06/2023] Open
Abstract
Redox active cysteine residues including βCys93 are part of hemoglobin's "oxidation hotspot". Irreversible oxidation of βCys93 ultimately leads to the collapse of the hemoglobin structure and release of heme. Human fetal hemoglobin (HbF), similarly to the adult hemoglobin (HbA), carries redox active γCys93 in the vicinity of the heme pocket. Site-directed mutagenesis has been used in this study to examine the impact of removal and/or addition of cysteine residues in HbF. The redox activities of the recombinant mutants were examined by determining the spontaneous autoxidation rate, the hydrogen peroxide induced ferric to ferryl oxidation rate, and irreversible oxidation of cysteine by quantitative mass spectrometry. We found that substitution of γCys93Ala resulted in oxidative instability characterized by increased oxidation rates. Moreover, the addition of a cysteine residue at α19 on the exposed surface of the α-chain altered the regular electron transfer pathway within the protein by forming an alternative oxidative site. This may also create an accessible site for di-sulfide bonding between Hb subunits. Engineering of cysteine residues at suitable locations may be useful as a tool for managing oxidation in a protein, and for Hb, a way to stave off oxidation reactions resulting in a protein structural collapse.
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Affiliation(s)
- Karin Kettisen
- Pure and Applied Biochemistry, Department of Chemistry, Lund University, Lund 22362, Sweden
| | - Michael Brad Strader
- Laboratory of Biochemistry and Vascular Biology, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Francine Wood
- Laboratory of Biochemistry and Vascular Biology, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Abdu I Alayash
- Laboratory of Biochemistry and Vascular Biology, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Leif Bülow
- Pure and Applied Biochemistry, Department of Chemistry, Lund University, Lund 22362, Sweden.
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8
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Weber RE, Jarvis JUM, Fago A, Bennett NC. O 2 binding and CO 2 sensitivity in haemoglobins of subterranean African mole rats. ACTA ACUST UNITED AC 2017; 220:3939-3948. [PMID: 28851819 DOI: 10.1242/jeb.160457] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 08/23/2017] [Indexed: 01/05/2023]
Abstract
Inhabiting deep and sealed subterranean burrows, mole rats exhibit a remarkable suite of specializations, including eusociality (living in colonies with single breeding queens), extraordinary longevity, cancer immunity and poikilothermy, and extreme tolerance of hypoxia and hypercapnia. With little information available on adjustments in haemoglobin (Hb) function that may mitigate the impact of exogenous and endogenous constraints on the uptake and internal transport of O2, we measured haematological characteristics, as well as Hb-O2 binding affinity and sensitivity to pH (Bohr effect), CO2, temperature and 2,3-diphosphoglycerate (DPG, the major allosteric modulator of Hb-O2 affinity in red blood cells) in four social and two solitary species of African mole rats (family Bathyergidae) originating from different biomes and soil types across Central and Southern Africa. We found no consistent patterns in haematocrit (Hct) and blood and red cell DPG and Hb concentrations or in intrinsic Hb-O2 affinity and its sensitivity to pH and DPG that correlate with burrowing, sociality and soil type. However, the results reveal low specific (pH independent) effects of CO2 on Hb-O2 affinity compared with humans that predictably safeguard pulmonary loading under hypoxic and hypercapnic burrow conditions. The O2 binding characteristics are discussed in relation to available information on the primary structure of Hbs from adult and developmental stages of mammals subjected to hypoxia and hypercapnia and the molecular mechanisms underlying functional variation in rodent Hbs.
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Affiliation(s)
- Roy E Weber
- Department of Bioscience, Aarhus University, C.F. Møllers Alle 3, Aarhus C 8000, Denmark
| | | | - Angela Fago
- Department of Bioscience, Aarhus University, C.F. Møllers Alle 3, Aarhus C 8000, Denmark
| | - Nigel C Bennett
- Zoology and Entomology Department, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
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9
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Regulation of blood oxygen transport in hibernating mammals. J Comp Physiol B 2017; 187:847-856. [DOI: 10.1007/s00360-017-1085-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 12/19/2016] [Accepted: 03/07/2017] [Indexed: 12/23/2022]
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10
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Storz JF. Gene Duplication and Evolutionary Innovations in Hemoglobin-Oxygen Transport. Physiology (Bethesda) 2017; 31:223-32. [PMID: 27053736 DOI: 10.1152/physiol.00060.2015] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
During vertebrate evolution, duplicated hemoglobin (Hb) genes diverged with respect to functional properties as well as the developmental timing of expression. For example, the subfamilies of genes that encode the different subunit chains of Hb are ontogenetically regulated such that functionally distinct Hb isoforms are expressed during different developmental stages. In some vertebrate taxa, functional differentiation between co-expressed Hb isoforms may also contribute to physiologically important divisions of labor.
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Affiliation(s)
- Jay F Storz
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska
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11
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Natarajan C, Projecto-Garcia J, Moriyama H, Weber RE, Muñoz-Fuentes V, Green AJ, Kopuchian C, Tubaro PL, Alza L, Bulgarella M, Smith MM, Wilson RE, Fago A, McCracken KG, Storz JF. Convergent Evolution of Hemoglobin Function in High-Altitude Andean Waterfowl Involves Limited Parallelism at the Molecular Sequence Level. PLoS Genet 2015; 11:e1005681. [PMID: 26637114 PMCID: PMC4670201 DOI: 10.1371/journal.pgen.1005681] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 10/27/2015] [Indexed: 11/18/2022] Open
Abstract
A fundamental question in evolutionary genetics concerns the extent to which adaptive phenotypic convergence is attributable to convergent or parallel changes at the molecular sequence level. Here we report a comparative analysis of hemoglobin (Hb) function in eight phylogenetically replicated pairs of high- and low-altitude waterfowl taxa to test for convergence in the oxygenation properties of Hb, and to assess the extent to which convergence in biochemical phenotype is attributable to repeated amino acid replacements. Functional experiments on native Hb variants and protein engineering experiments based on site-directed mutagenesis revealed the phenotypic effects of specific amino acid replacements that were responsible for convergent increases in Hb-O2 affinity in multiple high-altitude taxa. In six of the eight taxon pairs, high-altitude taxa evolved derived increases in Hb-O2 affinity that were caused by a combination of unique replacements, parallel replacements (involving identical-by-state variants with independent mutational origins in different lineages), and collateral replacements (involving shared, identical-by-descent variants derived via introgressive hybridization). In genome scans of nucleotide differentiation involving high- and low-altitude populations of three separate species, function-altering amino acid polymorphisms in the globin genes emerged as highly significant outliers, providing independent evidence for adaptive divergence in Hb function. The experimental results demonstrate that convergent changes in protein function can occur through multiple historical paths, and can involve multiple possible mutations. Most cases of convergence in Hb function did not involve parallel substitutions and most parallel substitutions did not affect Hb-O2 affinity, indicating that the repeatability of phenotypic evolution does not require parallelism at the molecular level. The convergent evolution of similar traits in different species could be due to repeated changes at the genetic level or different changes that produce the same phenotypic effect. To investigate the extent to which convergence in phenotype is caused by repeated mutations, we investigated the molecular basis of convergent changes in the oxygenation properties of hemoglobin (Hb) in eight pairs of high- and low-altitude waterfowl taxa from the Andes. The results revealed that convergent increases in Hb-O2 affinity in highland taxa involved a combination of unique and repeated amino acid replacements. However, convergent changes in Hb function generally did not involve parallel substitutions, indicating that repeatability in the evolution of protein function does not require repeatability at the sequence level.
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Affiliation(s)
- Chandrasekhar Natarajan
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Joana Projecto-Garcia
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Hideaki Moriyama
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Roy E. Weber
- Department of Bioscience, Zoophysiology, Aarhus University, Aarhus, Denmark
| | - Violeta Muñoz-Fuentes
- Estación Biológica de Doñana-CSIC, Sevilla, Spain
- Conservation Genetics Group, Senckenberg Research Institute and Natural History Museum Frankfurt, Gelnhausen, Germany
| | | | - Cecilia Kopuchian
- Centro de Ecología Aplicada del Litoral (CECOAL), Consejo Nacional de Investigaciones Cientificas y Técnicas (CONICET), Corrientes, Argentina
| | - Pablo L. Tubaro
- División Ornitología, Museo Argentino de Ciencias Naturales ‘Bernardino Rivadavia’ (MACN-CONICET), Buenos Aires, Argentina
| | - Luis Alza
- Institute of Arctic Biology and University of Alaska Museum, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
| | - Mariana Bulgarella
- Institute of Arctic Biology and University of Alaska Museum, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
| | - Matthew M. Smith
- Institute of Arctic Biology and University of Alaska Museum, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
| | - Robert E. Wilson
- Institute of Arctic Biology and University of Alaska Museum, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
| | - Angela Fago
- Department of Bioscience, Zoophysiology, Aarhus University, Aarhus, Denmark
| | - Kevin G. McCracken
- Institute of Arctic Biology and University of Alaska Museum, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
- Department of Biology and Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Coral Gables, Florida, United States of America
| | - Jay F. Storz
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
- * E-mail:
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12
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Contribution of a mutational hot spot to hemoglobin adaptation in high-altitude Andean house wrens. Proc Natl Acad Sci U S A 2015; 112:13958-63. [PMID: 26460028 DOI: 10.1073/pnas.1507300112] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A key question in evolutionary genetics is why certain mutations or certain types of mutation make disproportionate contributions to adaptive phenotypic evolution. In principle, the preferential fixation of particular mutations could stem directly from variation in the underlying rate of mutation to function-altering alleles. However, the influence of mutation bias on the genetic architecture of phenotypic evolution is difficult to evaluate because data on rates of mutation to function-altering alleles are seldom available. Here, we report the discovery that a single point mutation at a highly mutable site in the β(A)-globin gene has contributed to an evolutionary change in hemoglobin (Hb) function in high-altitude Andean house wrens (Troglodytes aedon). Results of experiments on native Hb variants and engineered, recombinant Hb mutants demonstrate that a nonsynonymous mutation at a CpG dinucleotide in the β(A)-globin gene is responsible for an evolved difference in Hb-O2 affinity between high- and low-altitude house wren populations. Moreover, patterns of genomic differentiation between high- and low-altitude populations suggest that altitudinal differentiation in allele frequencies at the causal amino acid polymorphism reflects a history of spatially varying selection. The experimental results highlight the influence of mutation rate on the genetic basis of phenotypic evolution by demonstrating that a large-effect allele at a highly mutable CpG site has promoted physiological differentiation in blood O2 transport capacity between house wren populations that are native to different elevations.
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13
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Storz JF, Natarajan C, Moriyama H, Hoffmann FG, Wang T, Fago A, Malte H, Overgaard J, Weber RE. Oxygenation properties and isoform diversity of snake hemoglobins. Am J Physiol Regul Integr Comp Physiol 2015; 309:R1178-91. [PMID: 26354849 DOI: 10.1152/ajpregu.00327.2015] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 09/02/2015] [Indexed: 11/22/2022]
Abstract
Available data suggest that snake hemoglobins (Hbs) are characterized by a combination of unusual structural and functional properties relative to the Hbs of other amniote vertebrates, including oxygenation-linked tetramer-dimer dissociation. However, standardized comparative data are lacking for snake Hbs, and the Hb isoform composition of snake red blood cells has not been systematically characterized. Here we present the results of an integrated analysis of snake Hbs and the underlying α- and β-type globin genes to characterize 1) Hb isoform composition of definitive erythrocytes, and 2) the oxygenation properties of isolated isoforms as well as composite hemolysates. We used species from three families as subjects for experimental studies of Hb function: South American rattlesnake, Crotalus durissus (Viperidae); Indian python, Python molurus (Pythonidae); and yellow-bellied sea snake, Pelamis platura (Elapidae). We analyzed allosteric properties of snake Hbs in terms of the Monod-Wyman-Changeux model and Adair four-step thermodynamic model. Hbs from each of the three species exhibited high intrinsic O2 affinities, low cooperativities, small Bohr factors in the absence of phosphates, and high sensitivities to ATP. Oxygenation properties of the snake Hbs could be explained entirely by allosteric transitions in the quaternary structure of intact tetramers, suggesting that ligation-dependent dissociation of Hb tetramers into αβ-dimers is not a universal feature of snake Hbs. Surprisingly, the major Hb isoform of the South American rattlesnake is homologous to the minor HbD of other amniotes and, contrary to the pattern of Hb isoform differentiation in birds and turtles, exhibits a lower O2 affinity than the HbA isoform.
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Affiliation(s)
- Jay F Storz
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska;
| | | | - Hideaki Moriyama
- School of Biological Sciences, University of Nebraska, Lincoln, Nebraska
| | - Federico G Hoffmann
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University, Starkville, Mississippi; Institute for Genomics, Biocomputing, and Biotechnology, Mississippi State University, Mississippi State, Mississippi; and
| | - Tobias Wang
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Angela Fago
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Hans Malte
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Johannes Overgaard
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Roy E Weber
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
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14
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Kotlík P, Marková S, Vojtek L, Stratil A, Slechta V, Hyršl P, Searle JB. Adaptive phylogeography: functional divergence between haemoglobins derived from different glacial refugia in the bank vole. Proc Biol Sci 2015; 281:rspb.2014.0021. [PMID: 24827438 DOI: 10.1098/rspb.2014.0021] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Over the years, researchers have used presumptively neutral molecular variation to infer the origins of current species' distributions in northern latitudes (especially Europe). However, several reported examples of genic and chromosomal replacements suggest that end-glacial colonizations of particular northern areas may have involved genetic input from different source populations at different times, coupled with competition and selection. We investigate the functional consequences of differences between two bank vole (Clethrionomys glareolus) haemoglobins deriving from different glacial refugia, one of which partially replaced the other in Britain during end-glacial climate warming. This allows us to examine their adaptive divergence and hence a possible role of selection in the replacement. We determine the amino acid substitution Ser52Cys in the major expressed β-globin gene as the allelic difference. We use structural modelling to reveal that the protein environment renders the 52Cys thiol a highly reactive functional group and we show its reactivity in vitro. We demonstrate that possessing the reactive thiol in haemoglobin increases the resistance of bank vole erythrocytes to oxidative stress. Our study thus provides striking evidence for physiological differences between products of genic variants that spread at the expense of one another during colonization of an area from different glacial refugia.
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Affiliation(s)
- Petr Kotlík
- Laboratory of Molecular Ecology, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Liběchov 27721, Czech Republic
| | - Silvia Marková
- Laboratory of Molecular Ecology, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Liběchov 27721, Czech Republic
| | - Libor Vojtek
- Department of Animal Physiology and Immunology, Institute of Experimental Biology, Faculty of Science, Masaryk University, Brno 61137, Czech Republic
| | - Antonín Stratil
- Laboratory of Molecular Ecology, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Liběchov 27721, Czech Republic
| | - Vlastimil Slechta
- Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Liběchov 27721, Czech Republic
| | - Pavel Hyršl
- Department of Animal Physiology and Immunology, Institute of Experimental Biology, Faculty of Science, Masaryk University, Brno 61137, Czech Republic
| | - Jeremy B Searle
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
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15
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Natarajan C, Hoffmann FG, Lanier HC, Wolf CJ, Cheviron ZA, Spangler ML, Weber RE, Fago A, Storz JF. Intraspecific polymorphism, interspecific divergence, and the origins of function-altering mutations in deer mouse hemoglobin. Mol Biol Evol 2015; 32:978-97. [PMID: 25556236 PMCID: PMC4379404 DOI: 10.1093/molbev/msu403] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Major challenges for illuminating the genetic basis of phenotypic evolution are to identify causative mutations, to quantify their functional effects, to trace their origins as new or preexisting variants, and to assess the manner in which segregating variation is transduced into species differences. Here, we report an experimental analysis of genetic variation in hemoglobin (Hb) function within and among species of Peromyscus mice that are native to different elevations. A multilocus survey of sequence variation in the duplicated HBA and HBB genes in Peromyscus maniculatus revealed that function-altering amino acid variants are widely shared among geographically disparate populations from different elevations, and numerous amino acid polymorphisms are also shared with closely related species. Variation in Hb-O2 affinity within and among populations of P. maniculatus is attributable to numerous amino acid mutations that have individually small effects. One especially surprising feature of the Hb polymorphism in P. maniculatus is that an appreciable fraction of functional standing variation in the two transcriptionally active HBA paralogs is attributable to recurrent gene conversion from a tandemly linked HBA pseudogene. Moreover, transpecific polymorphism in the duplicated HBA genes is not solely attributable to incomplete lineage sorting or introgressive hybridization; instead, it is mainly attributable to recurrent interparalog gene conversion that has occurred independently in different species. Partly as a result of concerted evolution between tandemly duplicated globin genes, the same amino acid changes that contribute to variation in Hb function within P. maniculatus also contribute to divergence in Hb function among different species of Peromyscus. In the case of function-altering Hb mutations in Peromyscus, there is no qualitative or quantitative distinction between segregating variants within species and fixed differences between species.
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Affiliation(s)
| | - Federico G Hoffmann
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University
| | - Hayley C Lanier
- Department of Zoology and Physiology, University of Wyoming at Casper
| | - Cole J Wolf
- Department of Animal Biology, School of Integrative Biology, University of Illinois, Urbana-Champaign
| | - Zachary A Cheviron
- Department of Animal Biology, School of Integrative Biology, University of Illinois, Urbana-Champaign
| | | | - Roy E Weber
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Angela Fago
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Jay F Storz
- School of Biological Sciences, University of Nebraska, Lincoln
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16
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Tufts DM, Natarajan C, Revsbech IG, Projecto-Garcia J, Hoffmann FG, Weber RE, Fago A, Moriyama H, Storz JF. Epistasis constrains mutational pathways of hemoglobin adaptation in high-altitude pikas. Mol Biol Evol 2014; 32:287-98. [PMID: 25415962 PMCID: PMC4298171 DOI: 10.1093/molbev/msu311] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
A fundamental question in evolutionary genetics concerns the roles of mutational pleiotropy and epistasis in shaping trajectories of protein evolution. This question can be addressed most directly by using site-directed mutagenesis to explore the mutational landscape of protein function in experimentally defined regions of sequence space. Here, we evaluate how pleiotropic trade-offs and epistatic interactions influence the accessibility of alternative mutational pathways during the adaptive evolution of hemoglobin (Hb) function in high-altitude pikas (Mammalia: Lagomorpha). By combining ancestral protein resurrection with a combinatorial protein-engineering approach, we examined the functional effects of sequential mutational steps in all possible pathways that produced an increased Hb–O2 affinity. These experiments revealed that the effects of mutations on Hb–O2 affinity are highly dependent on the temporal order in which they occur: Each of three β-chain substitutions produced a significant increase in Hb–O2 affinity on the ancestral genetic background, but two of these substitutions produced opposite effects when they occurred as later steps in the pathway. The experiments revealed pervasive epistasis for Hb–O2 affinity, but affinity-altering mutations produced no significant pleiotropic trade-offs. These results provide insights into the properties of adaptive substitutions in naturally evolved proteins and suggest that the accessibility of alternative mutational pathways may be more strongly constrained by sign epistasis for positively selected biochemical phenotypes than by antagonistic pleiotropy.
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Affiliation(s)
| | | | - Inge G Revsbech
- Department of Bioscience, Zoophysiology, Aarhus University, Aarhus, Denmark
| | | | - Federico G Hoffmann
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University
| | - Roy E Weber
- Department of Bioscience, Zoophysiology, Aarhus University, Aarhus, Denmark
| | - Angela Fago
- Department of Bioscience, Zoophysiology, Aarhus University, Aarhus, Denmark
| | | | - Jay F Storz
- School of Biological Sciences, University of Nebraska, Lincoln
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17
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Cheviron ZA, Natarajan C, Projecto-Garcia J, Eddy DK, Jones J, Carling MD, Witt CC, Moriyama H, Weber RE, Fago A, Storz JF. Integrating evolutionary and functional tests of adaptive hypotheses: a case study of altitudinal differentiation in hemoglobin function in an Andean Sparrow, Zonotrichia capensis. Mol Biol Evol 2014; 31:2948-62. [PMID: 25135942 PMCID: PMC4209134 DOI: 10.1093/molbev/msu234] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In air-breathing vertebrates, the physiologically optimal blood-O2 affinity is jointly determined by the prevailing partial pressure of atmospheric O2, the efficacy of pulmonary O2 transfer, and internal metabolic demands. Consequently, genetic variation in the oxygenation properties of hemoglobin (Hb) may be subject to spatially varying selection in species with broad elevational distributions. Here we report the results of a combined functional and evolutionary analysis of Hb polymorphism in the rufous-collared sparrow (Zonotrichia capensis), a species that is continuously distributed across a steep elevational gradient on the Pacific slope of the Peruvian Andes. We integrated a population genomic analysis that included all postnatally expressed Hb genes with functional studies of naturally occurring Hb variants, as well as recombinant Hb (rHb) mutants that were engineered through site-directed mutagenesis. We identified three clinally varying amino acid polymorphisms: Two in the α(A)-globin gene, which encodes the α-chain subunits of the major HbA isoform, and one in the α(D)-globin gene, which encodes the α-chain subunits of the minor HbD isoform. We then constructed and experimentally tested single- and double-mutant rHbs representing each of the alternative α(A)-globin genotypes that predominate at different elevations. Although the locus-specific patterns of altitudinal differentiation suggested a history of spatially varying selection acting on Hb polymorphism, the experimental tests demonstrated that the observed amino acid mutations have no discernible effect on respiratory properties of the HbA or HbD isoforms. These results highlight the importance of experimentally validating the hypothesized effects of genetic changes in protein function to avoid the pitfalls of adaptive storytelling.
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Affiliation(s)
- Zachary A Cheviron
- Department of Animal Biology, School of Integrative Biology, University of Illinois, Urbana-Champaign School of Biological Sciences, University of Nebraska, Lincoln
| | | | | | - Douglas K Eddy
- Department of Animal Biology, School of Integrative Biology, University of Illinois, Urbana-Champaign
| | - Jennifer Jones
- Department of Animal Biology, School of Integrative Biology, University of Illinois, Urbana-Champaign
| | | | - Christopher C Witt
- Department of Biology, University of New Mexico Museum of Southwestern Biology, University of New Mexico
| | | | - Roy E Weber
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Angela Fago
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Jay F Storz
- School of Biological Sciences, University of Nebraska, Lincoln
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18
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Revsbech IG, Tufts DM, Projecto-Garcia J, Moriyama H, Weber RE, Storz JF, Fago A. Hemoglobin function and allosteric regulation in semi-fossorial rodents (family Sciuridae) with different altitudinal ranges. ACTA ACUST UNITED AC 2014; 216:4264-71. [PMID: 24172889 DOI: 10.1242/jeb.091397] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Semi-fossorial ground squirrels face challenges to respiratory gas transport associated with the chronic hypoxia and hypercapnia of underground burrows, and such challenges are compounded in species that are native to high altitude. During hibernation, such species must also contend with vicissitudes of blood gas concentrations and plasma pH caused by episodic breathing. Here, we report an analysis of hemoglobin (Hb) function in six species of marmotine ground squirrels with different altitudinal distributions. Regardless of their native altitude, all species have high Hb-O2 affinities, mainly due to suppressed sensitivities to allosteric effectors [2,3-diphosphoglycerate (DPG) and chloride ions]. This suppressed anion sensitivity is surprising given that all canonical anion-binding sites are conserved. Two sciurid species, the golden-mantled and thirteen-lined ground squirrel, have Hb-O2 affinities that are characterized by high pH sensitivity and low thermal sensitivity relative to the Hbs of humans and other mammals. The pronounced Bohr effect is surprising in light of highly unusual amino acid substitutions at the C-termini that are known to abolish the Bohr effect in human HbA. Taken together, the high O2 affinity of sciurid Hbs suggests an enhanced capacity for pulmonary O2 loading under hypoxic and hypercapnic conditions, while the large Bohr effect should help to ensure efficient O2 unloading in tissue capillaries. In spite of the relatively low thermal sensitivities of the sciurid Hbs, our results indicate that the effect of hypothermia on Hb oxygenation is the main factor contributing to the increased blood-O2 affinity in hibernating ground squirrels.
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Affiliation(s)
- Inge G Revsbech
- Zoophysiology, Department of Bioscience, Aarhus University, C.F. Møllers Allè 3, DK-8000 Aarhus C, Denmark
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19
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Genome-wide adaptive complexes to underground stresses in blind mole rats Spalax. Nat Commun 2014; 5:3966. [DOI: 10.1038/ncomms4966] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 04/28/2014] [Indexed: 12/20/2022] Open
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20
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Kan HI, Chen IY, Zulfajri M, Wang CC. Subunit disassembly pathway of human hemoglobin revealing the site-specific role of its cysteine residues. J Phys Chem B 2013; 117:9831-9. [PMID: 23902424 DOI: 10.1021/jp402292b] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cysteine residues play a unique role in human hemoglobin (Hb) by affecting its cooperative oxygen binding behavior and the stability of its tetrameric structure. However, how these cysteine residues fulfill their biophysical functions from the molecular level is yet unclear. Here we study the subunit disassembly pathway of human hemoglobin using the sulfhydryl reagent, p-hydroxymercuribenzoate (PMB) and investigate the functional roles of cysteine residues in human hemoglobin. We show evidence from the matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry that all three types of cysteine residues, including the surface-exposed βCys93 and the shielded αCys104 and βCys112 are reactive to PMB, resolving an issue long under debate. It is demonstrated that all three types of cysteine residues must be blocked by PMB to accomplish the subunit disassembly, and the PMB-cysteine reactions proceed in a stepwise manner with an order of βCys93, αCys104, and βCys112. The PMB reactions with the three different cysteine residues demonstrate strong site-specificity. The possible influence of PMB-cysteine reactions to the stability of various intersubunit salt bridges has been discussed based on the crystallographic structure of hemoglobin, providing insights in understanding the hemoglobin subunit disassembly pathway and the site-specific functional role of each cysteine residue in hemoglobin.
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Affiliation(s)
- Heng-I Kan
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan, R.O.C. 80424
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21
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Inoguchi N, Oshlo JR, Natarajan C, Weber RE, Fago A, Storz JF, Moriyama H. Deer mouse hemoglobin exhibits a lowered oxygen affinity owing to mobility of the E helix. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:393-8. [PMID: 23545644 PMCID: PMC3614163 DOI: 10.1107/s1744309113005708] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 02/27/2013] [Indexed: 11/10/2022]
Abstract
The deer mouse, Peromyscus maniculatus, exhibits altitude-associated variation in hemoglobin oxygen affinity. To examine the structural basis of this functional variation, the structure of the hemoglobin was solved. Recombinant hemoglobin was expressed in Escherichia coli and was purified by ion-exchange chromatography. Recombinant hemoglobin was crystallized by the hanging-drop vapor-diffusion method using polyethylene glycol as a precipitant. The obtained orthorhombic crystal contained two subunits in the asymmetric unit. The refined structure was interpreted as the aquo-met form. Structural comparisons were performed among hemoglobins from deer mouse, house mouse and human. In contrast to human hemoglobin, deer mouse hemoglobin lacks the hydrogen bond between α1Trp14 in the A helix and α1Thr67 in the E helix owing to the Thr67Ala substitution. In addition, deer mouse hemoglobin has a unique hydrogen bond at the α1β1 interface between residues α1Cys34 and β1Ser128.
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Affiliation(s)
- Noriko Inoguchi
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Jake R. Oshlo
- Nebraska Wesleyan University, Lincoln, Nebraska, USA
| | | | - Roy E. Weber
- Zoophysiology, Department of Biological Sciences, Aarhus University, Aarhus, Denmark
| | - Angela Fago
- Zoophysiology, Department of Biological Sciences, Aarhus University, Aarhus, Denmark
| | - Jay F. Storz
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Hideaki Moriyama
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
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22
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Vitturi DA, Sun CW, Harper VM, Thrash-Williams B, Cantu-Medellin N, Chacko BK, Peng N, Dai Y, Michael Wyss J, Townes T, Patel RP. Antioxidant functions for the hemoglobin β93 cysteine residue in erythrocytes and in the vascular compartment in vivo. Free Radic Biol Med 2013; 55:119-29. [PMID: 23159546 PMCID: PMC3821075 DOI: 10.1016/j.freeradbiomed.2012.11.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Revised: 09/29/2012] [Accepted: 11/06/2012] [Indexed: 12/25/2022]
Abstract
The β93 cysteine (β93Cys) residue of hemoglobin is conserved in vertebrates but its function in the red blood cell (RBC) remains unclear. Because this residue is present at concentrations more than 2 orders of magnitude higher than enzymatic components of the RBC antioxidant network, a role in the scavenging of reactive species was hypothesized. Initial studies utilizing mice that express human hemoglobin with either Cys (B93C) or Ala (B93A) at the β93 position demonstrated that loss of the β93Cys did not affect activities nor expression of established components of the RBC antioxidant network (catalase, superoxide dismutase, peroxiredoxin-2, glutathione peroxidase, GSH:GSSG ratios). Interestingly, exogenous addition to RBCs of reactive species that are involved in vascular inflammation demonstrated a role for the β93Cys in hydrogen peroxide and chloramine consumption. To simulate oxidative stress and inflammation in vivo, mice were challenged with lipopolysaccharide (LPS). Notably, LPS induced a greater degree of hypotension and lung injury in B93A versus B93C mice, which was associated with greater formation of RBC reactive species and accumulation of DMPO-reactive epitopes in the lung. These data suggest that the β93Cys is an important effector within the RBC antioxidant network, contributing to the modulation of tissue injury during vascular inflammation.
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Affiliation(s)
| | - Chiao-Wang Sun
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham
| | | | | | | | - Balu K. Chacko
- Department of Pathology, University of Alabama at Birmingham
| | - Ning Peng
- Department of Pediatrics and Cell Biology, University of Alabama at Birmingham
| | - Yanying Dai
- Department of Pediatrics and Cell Biology, University of Alabama at Birmingham
| | - J. Michael Wyss
- Department of Pediatrics and Cell Biology, University of Alabama at Birmingham
| | - Tim Townes
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham
| | - Rakesh P. Patel
- Department of Pathology, University of Alabama at Birmingham
- Center for Free Radical Biology, University of Alabama at Birmingham
- Corresponding Author: Rakesh P Patel, PhD, Department of Pathology, University of Alabama at Birmingham, 901 19 street south, BMR-2, room 532, Birmingham, AL 35294, , Tel: 205 975 9225
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23
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Tufts DM, Revsbech IG, Cheviron ZA, Weber RE, Fago A, Storz JF. Phenotypic plasticity in blood-oxygen transport in highland and lowland deer mice. ACTA ACUST UNITED AC 2012; 216:1167-73. [PMID: 23239893 DOI: 10.1242/jeb.079848] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In vertebrates living at high altitude, arterial hypoxemia may be ameliorated by reversible changes in the oxygen-carrying capacity of the blood (regulated by erythropoiesis) and/or changes in blood-oxygen affinity (regulated by allosteric effectors of hemoglobin function). These hematological traits often differ between taxa that are native to different elevational zones, but it is often unknown whether the observed physiological differences reflect fixed, genetically based differences or environmentally induced acclimatization responses (phenotypic plasticity). Here, we report measurements of hematological traits related to blood-O2 transport in populations of deer mice (Peromyscus maniculatus) that are native to high- and low-altitude environments. We conducted a common-garden breeding experiment to assess whether altitude-related physiological differences were attributable to developmental plasticity and/or physiological plasticity during adulthood. Under conditions prevailing in their native habitats, high-altitude deer mice from the Rocky Mountains exhibited a number of pronounced hematological differences relative to low-altitude conspecifics from the Great Plains: higher hemoglobin concentrations, higher hematocrits, higher erythrocytic concentrations of 2,3-diphosphoglycerate (an allosteric regulator of hemoglobin-oxygen affinity), lower mean corpuscular hemoglobin concentrations and smaller red blood cells. However, these differences disappeared after 6 weeks of acclimation to normoxia at low altitude. The measured traits were also indistinguishable between the F1 progeny of highland and lowland mice, indicating that there were no persistent differences in phenotype that could be attributed to developmental plasticity. These results indicate that the naturally occurring hematological differences between highland and lowland mice are environmentally induced and are largely attributable to physiological plasticity during adulthood.
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Affiliation(s)
- Danielle M Tufts
- School of Biological Sciences, University of Nebraska, Lincoln, NE 68588, USA.
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